The present invention relates to an attachment arrangement, and more particularly to an attachment arrangement for components mounting within a vehicle transmission.
A hydraulically operated vehicle transmission is typically equipped with multiple frictional engaging elements such as hydraulic clutches, disks, brakes and the like that are engaged and disengaged by supplying/discharging operating oil to/from the frictional engaging elements. Proper operation and timing of the shift is achieved by optimizing the oil pressure for engagement/disengagement. The detection of the state of the clutch or other such frictional engagement elements is typically achieved by detecting the engaging oil pressure through an oil pressure sensor. The oil pressure sensor communicates with a transmission electronic control unit which commands the gear shit timing.
Ordinarily, the sensor is located within the transmission case which subjects the sensor to an extremely difficult environment. As a result, these components must be connected in a manner which is robust and impervious to the environment within the transmission case. Typically, multiple wire harnesses connect individual sensors to a connector extending through the transmission case. An external wire harness then provides communication between the sensors and the transmission electronic control unit. Only the sensors and their wire connections are located within the transmission case to avoid subjecting the electronic control unit to the difficult environment within the transmission case. Disadvantageously, the wire connections must routed within the transmission case to avoid multiple moving transmission components. In addition to the weight penalty of multiple wire harnesses, the routing may become rather complex and multiple wire connections may increase the possibility of failure.
Accordingly, it is desirable to provide a compact mounting arrangement for sensors and associated components which are resistant to the environment within a transmission case while minimizing wire connections and providing advantageous assembly versatility.
The transmission system according to the present invention provides a transmission housing having a mechatronics control module mounted therein. The mechatronics control module includes an electronic control unit having a flex foil circuit for the mounting of multiple electronic components including sensors which sense the hydraulic state of elements within the transmission system.
One embodiment of a method for mounting the sensor includes laminating the flex foil to a base plate such that the circuit traces are located opposite the base plate. A flex foil flap which was previously cut into the flex foil is aligned adjacent to an opening in the base plate.
A fixture having an extension is aligned with the opening and folds the flap such that flap is pushed substantially perpendicular to the opening. The sensor is mounted to the base plate such that the contacts which extends from the sensor, clears the folded flap and are received within a recess in the fixture. The base plate and mounted sensor are removed from the fixture and the flap unfolds so that the circuit traces of the flex foil are now adjacent the contacts. In a final step, the circuit traces are electrically connected to the contacts by laser welding or the like.
The present invention therefore provides a compact mounting arrangement for sensors and associated components which are resistant to the environment within a transmission case, minimize wire connections, and provide extensive assembly versatility.